Merge Layers (Cmd+E) with no group included in the selection will preserve off-canvas pixels.
Merge Layers (Cmd+E) with group(s) included in the selection will remove off-canvas pixels.
Merge Groups (Cmd+E) removes off-canvas pixels.
A workaround to preserve off-canvas pixels when merging group(s) or a combined selection of group(s) and layer(s):
Ungroup Layers (Shift+Cmd+G), Merge Layers (Cmd+E)
Hadn’t tested for groups, but as the OP’s claim regarding »merging layers« seemed plainly incorrect it did not seem important to me.
The behaviour for Groups seems unexpected indeed, but if the issue is connected to the newly improved features of Groups in CS6 I wonder if it can easily be remedied.
I'd be horrified if Adobe are constructing software in such a way that it prevents an easy remedy to this :)
Of course, a change will depend on whether Adobe will desire to change the group merging behaviour.
At least one customer dislikes the behaviour so I guess they will at least consider making the change.
As for the easy remedy: I’m no programmer so I’m just guessing ... the new behaviour like the ability to use a Group as the base of a Clipping Mask might have necessitated introducing some »intermediate level« that might be problematic with regard to performance if off-canvas content would be included.
And then there’s the issue that with an application as voluminous as Photoshop changing anything at all might be risky ...
Quote: "And then there’s the issue that with an application as voluminous as Photoshop changing anything at all might be risky ..."
That's what my "horrified" comment regards. It would have been shockingly bad practice if the software is constructed in a way that prevents implementing the particular change in group-merge behaviour which we're discussing. Please realise that I am not suggesting that the bad practice has occurred. On the contrary, I'm confident that the only reason we'll not see a change is if Adobe do not want to make the change.
Thanks Connor. Your workaround works... as by brother who uses CS6 also pointed out to me. I hope it's a bug that gets fixed as it drives me crazy. I use PS every day as a freelance illustrator. In fact I've purchased and used nearly every iteration of PS since version 2.0. Yes, that's a long time with this software. I could get used to the workaround or create an action to group-ungroup-merge layers, but I hope Adobe fixes it. Frankly I'm surprised this bug would be created by the new CS6 "update" release.
I also tried this simple experiment using filters on layers.
Create a shape, in my case a circle on an empty transparent layer. Fill it with pixels (any color). Drag it half outside the canvass. Applie a gaussian blur (high amount-- like 20 pixels). Drag the shape back onto the canvass and the right side of the shape blur is clipped. Strange and unacceptable.
Try it and see if it happens to you.
I found this bug using Photoshop CS6 on an actual job I was doing. I immediately closed my file and opened in CS5 and finished my job.
I can't use CS6 in its current form as my professional work would suffer too greatly. I REALLY hope someone at Adobe recognizes these bugs and fixes them.
Thanks again for your replies.
Actually, on the gaussian blur experiment. Drag the shape completely out of the canvas area. Apply the filter then bring it back. The shape will look like this-- clipped on the right:
Same here with CS6 on OS X 10.6.8. Like you said earlier, the target of the blur doesn't need to be completely outside the canvas for the clipped edge to occur. And blurs in addition to Gaussian are affected; maybe all of the blur filters.